Multiple access cellular communication with signal cancellation to reduce co-channel interference
First Claim
1. An apparatus for communicating information in slots of a frame in a system including a first base station adapted to communicate with users in a first cell, the first base station generating an interfering signal, the apparatus comprising:
- a second base station adapted to communicate with users in a second cell, the second base station receiving the interfering signal from the first base station as an interference component of a received composite signal, wherein the composite signal also includes an uplink information signal from a user in the second cell; and
a cancellation signal transmission path between the first base station and the second base station for supplying a cancellation signal representative of the interfering signal from the first base station to the second base station, wherein the cancellation signal is utilizable in the second base station to offset the interference component of the received composite signal.
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Accused Products
Abstract
A method and system for reducing co-channel interference (CCI) in multiple access communication by providing complete or partial cancellation of a mixed CCI interfering signal in a system base station. An exemplary system includes first and second base stations communicating with users in first and second cells, respectively. The first base station transmits a downlink signal to a user in the first cell. The downlink signal is also a mixed CCI interfering signal in that it interferes with reception of an uplink signal in the second base station. A cancellation signal representative of the interfering signal is supplied along a transmission path from the first base station to the second base station. The second base station utilizes the cancellation signal to reduce the effect of the interfering signal on a received composite signal by, for example, combining the cancellation signal or a suitably processed version thereof with the received composite signal. Other aspects of the invention involve reducing mixed CCI by providing non-uniform quality of service, by dropping potentially interfering packets, or by full or partial circular interleaving of packet slot assignments.
213 Citations
26 Claims
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1. An apparatus for communicating information in slots of a frame in a system including a first base station adapted to communicate with users in a first cell, the first base station generating an interfering signal, the apparatus comprising:
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a second base station adapted to communicate with users in a second cell, the second base station receiving the interfering signal from the first base station as an interference component of a received composite signal, wherein the composite signal also includes an uplink information signal from a user in the second cell; and a cancellation signal transmission path between the first base station and the second base station for supplying a cancellation signal representative of the interfering signal from the first base station to the second base station, wherein the cancellation signal is utilizable in the second base station to offset the interference component of the received composite signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for communicating information in slots of a frame in a system including a first base station associated with a first cell and generating an interfering signal corresponding to a downlink signal transmitted to a user in the first cell, and a second base station associated with a second cell receiving the interfering signal from the first base station as an interference component of a received composite signal, wherein the composite signal also includes an uplink information signal from a user in the second cell, the method comprising the steps of:
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transmitting a cancellation signal representative of the interfering signal from the first base station to the second base station; and utilizing the cancellation signal in the second base station to offset the interference component of the received composite signal. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A method for communicating information in slots of a frame comprising the steps of:
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providing a first base station associated with a first cell and adapted to transmit a downlink signal to a user in the first cell; providing a second base station associated with a second cell and adapted to receive an uplink signal from a mobile user in the second cell; determining dynamically if the downlink signal from the first base station interferes with reception of the uplink signal in the second base station; and controlling the signal transmission in at least one of the first and second base stations on an ongoing basis to reduce the likelihood that the downlink signal will interfere with the uplink signal. - View Dependent Claims (18, 19, 20)
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21. An apparatus for communicating information in slots of a frame in a system including a first base station adapted to communicate with users in a first cell, the first base station generating an interfering signal, the apparatus comprising:
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a second base station adapted to communicate with users in a second cell, the second base station receiving the interfering signal from the first base station as an interference component of a received composite signal, wherein the composite signal also includes an uplink information signal from a user in the second cell; and a cancellation signal transmission path between the first base station and the second base station for supplying a cancellation signal representative of the interfering signal from the first base station to the second base station, wherein the cancellation signal is utilizable in the second base station to offset the interference component of the received composite signal; and a system controller directing an operation of the first and second base stations and implementing a service in which a user in the second cell is assigned a frame slot position less susceptible to the interfering signal.
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22. An apparatus for communicating information in slots of a frame in a system including a first base station adapted to communicate with users in a first cell, the first base station generating an interfering signal, the apparatus comprising:
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a second base station adapted to communicate with users in a second cell, the second base station receiving the interfering signal from the first base station as an interference component of a received composite signal, wherein the composite signal also includes an uplink information signal from a user in the second cell; a cancellation signal transmission path between the first base station and the second base station for supplying a cancellation signal representative of the interfering signal from the first base station to the second base station, wherein the cancellation signal is utilizable in the second base station to offset the interference component of the received composite signal; and a system controller directing an operation of the first and second base stations and implementing a service in which the first base station is directed to drop a downlink packet of the interfering signal when a user is transmitting an uplink packet of the uplink information signal in the same frame slot to the second base station.
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23. An apparatus for communicating information in slots of a frame in a system including a first base station adapted to communicate with users in a first cell, the first base station generating an interfering signal, the apparatus comprising:
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a second base station adapted to communicate with users in a second cell, the second base station receiving the interfering signal from the first base station as an interference component of a received composite signal, wherein the composite signal also includes an uplink information signal from a user in the second cell; a cancellation signal transmission path between the first base station and the second base station for supplying a cancellation signal representative of the interfering signal from the first base station to the second base station, wherein the cancellation signal is utilizable in the second base station to offset the interference component of the received composite signal; and a system controller implementing a circular interleaving of frame slot assignments in the first and second base stations.
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24. A method for communicating information in slots of a frame in a system including a first base station associated with a first cell and generating an interfering signal corresponding to a downlink signal transmitted to a user in the first cell, and a second base station associated with a second cell receiving the interfering signal from the first base station as an interference component of a received composite signal, wherein the composite signal also includes an uplink information signal from a user in the second cell, the method comprising the steps of:
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transmitting a cancellation signal representative of the interfering signal from the first base station to the second base station; utilizing the cancellation signal in the second base station to offset the interference component of the received composite signal; and directing an operation of the first and second base stations to implement a service in which a user in the second cell is assigned a frame slot position less susceptible to the interfering signal.
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25. A method for communicating information in slots of a frame in a system including a first base station associated with a first cell and generating an interfering signal corresponding to a downlink signal transmitted to a user in the first cell, and a second base station associated with a second cell receiving the interfering signal from the first base station as an interference component of a received composite signal, wherein the composite signal also includes an uplink information signal from a user in the second cell, the method comprising the steps of:
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transmitting a cancellation signal representative of the interfering signal from the first base station to the second base station; utilizing the cancellation signal in the second base station to offset the interference component of the received composite signal; and directing an operation of the first and second base stations to implement a service in which the first base station is directed to drop a downlink packet of the interfering signal when a mobile user in the second cell is transmitting an uplink packet of the uplink information signal in the same frame slot.
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26. A method for communicating information in slots of a frame in a system including a first base station associated with a first cell and generating an interfering signal corresponding to a downlink signal transmitted to a user in the first cell, and a second base station associated with a second cell receiving the interfering signal from the first base station as an interference component of a received composite signal, wherein the composite signal also includes an uplink information signal from a user in the second cell, the method comprising the steps of:
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transmitting a cancellation signal representative of the interfering signal from the first base station to the second base station; utilizing the cancellation signal in the second base station to offset the interference component of the received composite signal; and providing a circular interleaving of frame slot assignments in the first and second base stations.
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Specification